Crystal structure and up-conversion luminescence properties of K3ScF6:Er3+,Yb3+ cryolite

In this paper, K 3 ScF 6 :Er 3+ ,Yb 3+ up-conversion luminescent materials with cryolite structure were synthesized via solid-state method. The X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL) under the excitation of a 980 nm laser with different power density were used to investigate the phase structure, elemental composition , and up-conversion luminescence properties of K 3 ScF 6 :Er 3+ ,Yb 3+ . The quenching concentrations of Yb 3+ and Er 3+ were confirmed to 0.15 and 0.05 (mol concentration) in this system, respectively. Upon 980 nm excitation, the K 3 ScF 6 :Er 3+ ,Yb 3+ showed a typical transition of Er 3+ which contains two main bands in the visible region that green and red. According to the fitting result of the pump power dependence of up-conversion intensity, all the green and red up-conversion emission of K 3 ScF 6 :0.05Er 3+ ,0.15 Yb 3+ belong to the two-photon process. To better understand the origin of radiation and energy transfer mechanism of the red and green up-conversion, the possible mechanism and electron transition process were also discussed.